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19 Enhancements IEEE 802.11ay was specifically designed to build on the established technology of IEEE 802.11ad. It offers enhancements to the previous amendment by introducing channel bonding and aggregation along with MIMO. Also, the new amendment offers a greater variety of beamforming techniques, which leads to a boost in maximum throughput of 80Gbps (when employing four spatial streams), compared to IEEE 802.11ad's 6.7Gbps (in a single stream), and an indoor/outdoor range of 10/100m, compared to 3/30m. Target Applications IEEE 802.11ay was designed to provide ultra-high-speed wireless connectivity between devices within reasonably close proximity (for example, 5 to 10m) and in the absence of obstacles such as walls. One such application is downloading high-definition (HD) movies to a smart TV. Early IEEE 802.11ay implementations that offer a data rate of 10Gbps can download a 4K movie (60GB) in just over a minute compared to more than 11 minutes for an IEEE 802.11ad installation. Other applications include virtual and augmented reality (VR and AR). For example, a gaming application and content on a managing device, such as a smartphone, could wirelessly transfer to a VR headset using an ultra-high-speed IEEE 802.11ay wireless link, all with no cellular or Internet link requirements (Figure 1). Another application that IEEE 802.11ay schemes such as notch filtering and dual sub-channel modulation. Second, the technology's narrower sub-channel space (78.125kHz) makes it more prone to frequency and phase errors and unwanted residual-center frequency offsets. Third, 1024-QAM presents design challenges such as non-linearity during power amplification, and 8 x 8 MU-MIMO connections demand more signal generations and analysis channels for testing. Finally, IEEE 802.11ax's complexity can cause quantization errors during analog-to-digital conversions and phase noise increases in local oscillators. IEEE 802.11ay While IEEE 802.11ax focuses on spectral efficiency, elsewhere IEEE 802.11 technical committees are considering amendments to the technology's physical and media access-control layers that dramatically increase the throughput of Wi-Fi for specialist applications. The latest of these amendments, IEEE 802.11ay, builds on IEEE 802.11ad and promises to boost throughput while helping to extend range. Technology IEEE 802.11ay was designed to operate in the unlicensed 60GHz spectrum allocation and is backward compatible with IEEE 802.11ad equipment. The allocation offers a frequency band of around 14GHz in width, which the amendment proposes dividing into 2.16, 4.32, 6.48, and 8.64GHz channels. IEEE 802.11ay brings MIMO operation to 60GHz Wi-Fi for the first time. The technology will offer "single-user" multiple input/multiple output (SU-MIMO) connections, downlink MU-MIMO (up to eight users), and up to four spatial streams. While exact details are yet to be released, it's likely that IEEE 802.11ay will use OFDM modulation; up to 256-QAM; and 5/8, 3/4, and 13/16 coding rates. Maximum throughput will be 20Gbps for a single stream. targets is the wireless backhaul that supplements cellular networks across short distances—for example, for wirelessly linking two adjacent office buildings on a commercial campus. Availability The IEEE 802.11ay technical committee estimates that the amendment's adoption will occur in late 2019. To date, commercial technology and development tools are not available for this amendment. Design Challenges While high-frequency Wi-Fi provides the inherent advantage of greater throughput, range limitations are present forcing engineers to turn to complex beamforming transmitters and multiple antennas to achieve satisfactory performance. Such complexity compounded with the challenges of high RF circuitry and printed circuit board (PCB) layouts pushes the so-called "gigabit" Wi-Fi a step above the more "routine" 2.4 and 5GHz technology. Signal analysis and testing of 60GHz Wi-Fi is also correspondingly more complex. Wi-Fi for IoT While much of the focus of the IEEE's working groups has been on improving Wi-Fi's throughput and spectral efficiency, complementary efforts have been in process to introduce amendments that make the technology applicable as a connectivity option for IoT. The demands of IoT are far removed from those of Wi-Fi's traditional target markets, such as wireless Ethernet where throughput is more important than range or power consumption. In contrast, an IoT application sensor data upload to the cloud demands a relatively infrequent transfer of low volumes of information. Low-power consumption is important because sensors typically operate from batteries for long periods, yet long-range capacity is an advantage because sensor deployment might span over a wide outdoor area in applications like traffic or security monitoring (Figure 2). Figure 1: IEEE 802.11ay meets the high- bandwidth demands of mobile VR applications. Source: (Getty Images)

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